Optic nerve sheath diameter trajectories and mortality in children with clinically relevant elevated intracranial pressure

Table 1 Baseline clinical characteristics of study participants on pediatric intensive care unit admissions and associated outcomes at discharge (n = 69), n (%)/median (25^th-75^th percentiles)

Characteristics	Statistics
Age, (years)	6 (1-12)
Male patients	37 (54)
Traumatic brain injury	27 (39)
Cerebrovascular disease	14 (20)
Cerebral infection	3 (4.4)
Septic shock	5 (7.3)
Hydrocephalus	5 (7.3)
Hepatic encephalopathy	3 (4.4)
Asphyxia due to drowning	3 (4.4)
Abnormal pupils	19 (28)
Abnormal posture	1 (1.5)
Seizure	23 (33)
Cushing triad syndrome	2 (2.9)
GCS on admission	7 (6-7)
ONSD on right eyes, (mm)
ONSD on PICU admission	5.3 (5-5.6)
ONSD at 24 hours	5.2 (4.9-5.5)
ONSD at 48 hours	5.0 (4.7-5.3)
ONSD on left eyes, (mm)
ONSD on PICU admission	5.4 (5-5.6)
ONSD at 24 hours	5.3 (4.9-5.5)
ONSD at 48 hours	5.2 (4.8-5.5)
Variability of mean ONSD at 48 hours compared to baseline levels, (%)	-4.8 (-7.4-1)
CT scan of brain performed	67 (97)
MRI of brain performed	11 (16)
Vasopressor use	41 (59)
Vasoactive inotropic score	15 (0-30)
PELOD-2 score	6 (4-9)
Treatments
Mannitol infusion	35 (51)
Hypertonic saline 3% infusion	67 (97)
Decompressive craniectomy	27 (39)
External ventricular drainage	4 (5.8)
Ventriculoperitoneal shunt	5 (7.2)
Patient outcomes at discharge
Length of mechanical ventilation, (days)	4.2 (3.3-5.2)
Fatal outcome	16 (23.2)

GCS: Glasgow Coma Scale; ONSD: Optic nerve sheath diameter; PELOD-2: Pediatric logistic organ dysfunction-2; PICU: Pediatric intensive care unit.

Table 2 Risk factors associated with fatal outcome in children with clinically relevant raised intracranial pressure, n (%)/median (25^th-75^th percentiles)

Characteristics	Survivors (n = 53)	Non-survivors (n = 16)	P value
Age, (years)	6 (1.4-13)	4.5 (1-9.4)	0.50
Male patients	27 (51)	10 (62)	0.42
Traumatic brain injury	24 (45)	3 (19)	0.11
Cerebral infection	1 (2)	2 (13)	0.13
Septic shock	0 (0)	5 (31)	< 0.001
Hydrocephalus	5 (9)	0 (0)	0.58
Hepatic encephalopathy	0 (0)	3 (19)	0.01
Asphyxia due to drowning	2 (4)	1 (6)	0.55
Abnormal pupils	10 (19)	9 (56)	< 0.01
Abnormal posture	1 (2)	0 (0)	0.77
Seizure	18 (34)	5 (31)	0.99
Cushing triad syndrome	1 (2)	1 (6)	0.41
Glasgow Coma Scale
GCS on PICU admission	7 (7-7)	5 (3-7)	< 0.001
GCS at 24 hours	7 (7-7)	3 (3-4)	< 0.001
GCS at 48 hours	7 (7-8)	3 (3-3)	< 0.001
ONSD on right eyes, (mm)
ONSD on PICU admission	5.2 (4.9-5.5)	5.5 (5.1-5.6)	0.35
ONSD at 24 hours	5.1 (4.8-5.3)	5.6 (5.27-5.73)	0.03
ONSD at 48 hours	5.0 (4.63-5.2)	5.74 (5.24-5.8)	< 0.001
ONSD on left eyes, (mm)
ONSD on PICU admission	5.4 (5.0-5.6)	5.4 (5.18-5.6)	0.65
ONSD at 24 hours	5.3 (4.9-5.5)	5.55 (5.19-5.8)	0.09
ONSD at 48 hours	5.1 (4.7-5.3)	5.66 (5.39-5.84)	0.003
Vasoactive inotropic score (VIS)	10 (0-20)	60 (30-90)	< 0.001
VIS > 30	4 (8)	14 (88)	< 0.001
PELOD-2 score	4 (4-6)	12 (11-15)	< 0.001
Mannitol infusion	27 (51)	8 (50)	0.99
Hypertonic saline 3% infusion	52 (98)	15 (91)	0.41
Decompressive craniectomy	21 (40)	6 (38)	0.99
Ventriculoperitoneal shunt	4 (8)	1 (6)	0.57
Length of mechanical ventilation, (days)	4.2 (3.5-5.0)	3.3 (2.9-5.9)	0.77
Length of PICU stay, (days)	4.6 (3.9-5.6)	3.3 (2.9-5.9)	0.90

GCS: Glasgow Coma Scale; ONSD: Optic nerve sheath diameter; PELOD-2: Pediatric logistic organ dysfunction-2; PICU: Pediatric intensive care unit.

Table 3 Linear mixed effects model for dynamic changes in optic nerve sheath diameter within 48 hours of pediatric intensive care unit admission in association with the survival outcome at discharge (n = 69)

Random effect analysis1	Variance	SD
Intercept	0.084	0.289
Residual	0.047	0.217
Fixed effect analysis	Estimate	SE	95%CI	P value
Baseline ONSD levels	0.837	0.032	0.774-0.899	< 0.001
GCS at admission	-0.047	0.015	-0.076 to -0.018	< 0.01
Death (yes)	0.125	0.058	0.011-0.238	0.03

¹Random effect accounted for 23% from linear mixed effects model.

GCS: Glasgow Coma Scale; ONSD: Optic nerve sheath diameter.

Table 4 Bivariate logistic analysis for association between the within 48 hours post-admission optic nerve sheath diameter variability and in-hospital mortality

Group	ONSD variability (%)	OR (95%CI), P value
Survivors (n = 53)	-5.6 (-8 to -3.6)	1.31 (1.14–1.5), P < 0.001
Nonsurvivors (n = 16)	5.3 (1.3-6.9)

OR: Odds ratio; ONSD: Optic nerve sheath diameter.

Table 5 Linear mixed effects model for dynamic variability in optic nerve sheath diameter within 48 hours of pediatric intensive care unit admission in patients with clinically relevant elevated intracranial pressure (n = 69)

Random effect1	Variance	SD
Intercept	0.048	0.219
Residual	0.047	0.216
Fixed effect	Estimate	SE	95%CI	P value
Baseline ONSD levels	0.841	0.029	0.784-0.898	< 0.001
GCS at discharge	-0.015	0.007	-0.029 to -0.001	0.03
VIS > 30	-0.004	0.059	-0.119 to 0.112	0.94
PELOD-2 score	-0.018	0.006	-0.029 to -0.006	0.002

¹Random effect accounted for approximately 45% from the linear mixed effects model.

GCS: Glasgow Coma Scale; ONSD: Optic nerve sheath diameter; PELOD-2: Pediatric logistic organ dysfunction-2; PICU: Pediatric intensive care unit; VIS: Vasoactive inotropic score.